This patch adds support for the controller's IMU. The accelerometer and
gyro data are both provided to userspace using a second input device.
The devices can be associated using their uniq value (set to the
controller's MAC address).

A large part of this patch's functionality was provided by Carl Mueller.

The IMU device is blacklisted from the joydev input handler.

Signed-off-by: Daniel J. Ogorchock <djogorchock@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>